Aircraft: B747
Phase of flight: Parked
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Weight And Balance

I was responsible for the Main Deck Inspection for the flight. The airplane had come in late and there was some time pressure as the airport was due to close 45 minutes after our rescheduled departure time. The airplane had come in from ZZZ1 with a full load of cargo; some of which was staying on and some of which was pulled off and replaced with new cargo. We were given a very confusing NOTOC [Notice to Captain] (multiple sections were crossed out and pen and ink changed due to the cargo being moved around) and 3 tie down worksheets as we had two cars and an aircraft engine that were being loaded there. I came downstairs to do the Main Deck Inspection as the ground crew was loading the last pallets. The ground crew was just starting to put the straps on as the main deck door was closed; but I noticed that they were not referencing the tie down worksheets at all. When I thought they were done I looked at the special loads and noticed that the actual straps didn't match the tied down worksheet at all. I made a comment about this to the Loadmaster who told me that they hadn't actually finished and would get everything fixed before we left. So I continued checking the other cargo and noticed that there was a pallet with a Hazmat tag at position SL; but I didn't have anything listed on the NOTOC. The Loadmasters were busy so I made a mental note to have them figure out the issue when they were done. After checking the other cargo I went back to check the special loads because the Loadmaster indicated they were done. I noticed that the actual tie down still didn't match the strap plan on the tie down worksheet so I brought the issue up with the Loadmaster. For the cars; the worksheet indicated a total of 8 straps needed; but I counted 12 straps instead. There were extra straps in some locations and missing straps in one or two places. Additionally some straps were secured to the pallet; and some were secured to the aircraft itself. The Loadmaster told me that it was fine; that the tie down worksheets were just 'generic'; and that 'sometimes we just make things work.' This went against everything I was taught and had seen up to this point on the line. It also didn't make sense because why would we have tie down worksheets if we weren't going to follow them. In ground school when I was hired; the Loadmaster who came into our class made a point of telling us that if we had special loads the straps had to match the plan exactly (no more or less straps; and each strap secured as the diagram showed us). Also; on the line I had had Loadmasters tell me the same thing. I told the Loadmaster what I had been taught in ground school and that I had never seen a special load not match its tie down worksheet diagram. I also told him that the Captain had given me the tie down worksheets and told me to make sure everything was tied down correctly; so we believed the straps needed to be redone so they matched the diagram. The Loadmaster was noticeably upset with me and tried telling me that it was strapped according to the diagram; but I showed him the worksheet and pointed to several sections on the cars where the straps were different from the diagram. It took some time to get everything fixed because instead of taking the diagram and redoing the work; he would change one strap and ask if I was happy and so it was up to me to point out every place that things were different. I don't know if this occurred because he was upset with me or if it was because he was unfamiliar with the use of the tie down worksheet. As the Loadmaster progressed through fixing the straps the time pressure began to ratchet up. At first the Loadmaster made comments indicating he was going to put the delay on Flight Crew Special Request because of me; and then later in the process the Loadmaster and his supervisor started saying that the airport was going to close soon and we would get stuck and completely mess up the schedule of the airplane. It was clear there was more ofa focus on on-time performance than on safety and legality. Through all of the comments I remained polite but I definitely felt the pressure growing. Eventually the Captain came down to see what was going on; I explained the situation and he backed me up to the Loadmaster and supervisor and said we needed to get it right. During this whole conversation I also brought up the incorrect NOTOC that was missing information on the pallet at SL which had a tag but no information. After some investigation it turned out the information was on the NOTOC but had been crossed out accidentally as it was near some other pallets that had been offloaded. The Loadmaster told me not to worry about it because it was there even though it was crossed out. I told him that having it crossed out while onboard was not okay and so he finally agreed to correct the NOTOC. It took a while to get everything straightened out; but we got out of ZZZZ shortly before it closed. While in cruise I had some time to look through the manuals on my EFB (something I should've done before we left but didn't because of the time pressure). While reading the manuals in the car section; I noticed that the straps in the manuals were secured to the pallet and not the aircraft. The diagram we had made it look like the straps should be attached to the aircraft; and that's how the Loadmasters set it up. But once the pressure was gone and I thought back to previous times I've carried cars; if I remember correctly; they've been strapped to the pallet instead. It could be that either way is acceptable; I'm not sure. I also couldn't find a clear reference that said the tie down worksheet and diagram needed to be followed exactly. While at the time of departure I believed that everything was secured properly; upon reading the manuals afterwards I'm no longer 100% sure everything was correct. From reading the manuals I think it was okay for the straps to be attached to the aircraft here; but I could be misunderstanding the situation. There was so much back and forth that things got a little confused after a while. Later I also noticed that in the process to get out of ZZZZ before it closed; no one signed the tie down verification line on the tie down worksheets. In retrospect; as much as I tried to resist the pressure and make sure everything was done properly; it still got me a little bit. I don't know if we just caught [station personnel] on a bad night; but it seemed like the station personnel in general weren't familiar with the use of the tie down worksheets. They weren't used during the tie down process and the Loadmaster seemed a little confused by it at times while we were working through the issues. And from the Loadmaster's comments it seems like the general station policy is to just throw straps on where they feel like it and call it good. For my reference I talked to the Loadmaster that met the flight at our destination to make sure I wasn't completely off base. I asked if the tie down worksheet should be followed when securing special loads and he confirmed that yes it should and stated that they 'always use the tie down worksheet.' Logically; and from what I was taught in training the tie down worksheet should be followed; but unless I missed something I couldn't find a clear reference that I could point to in the future if this situation came up again. It would be helpful it one of our manuals was changed to include a clear directive about whether or not the straps need to match the worksheet and also whether or not extra straps are acceptable. Additionally; during Operating Experience I was taught to check the straps and tie down worksheet; and Captains I've flown with have routinely expected this. However; [Operations Manual] doesn't explicitly state this; so if this is something we shouldn't be doing; then additional clarification should be provided to the pilot group. The tie down worksheets we were provided were black and white photocopies of the original color document which made the entire process more difficult since the straps are shown in different colors for clarity. There was a legend but it was very difficult to match the different straps since they were in black and white. A color copy would have been very helpful. Finally; assuming I'm not incorrect about the proper tie down procedures; the ZZZZ station could use some additional training on securing special loads as there seems to be some different views among the stations about this issue. If ZZZZ was correct; then additional clarification for everyone should be provided too. While loading the aircraft we had 2 cars and 2 engines loaded with tiedown worksheets. On inspection of the main deck we found the cars where not tied down per the tiedown worksheet. We brought this to the attention of the Loadmaster; and the cars where then tied down per the tiedown worksheet. We departed with a 54-minute delay. I was not intimately involved with the issues so I cannot speak directly to what exactly transpired; but to my understanding if a load is not properly secured we cannot leave the gate. B747 flight crew reported numerous procedure and documentation errors regarding Hazmat shipment due to inconsistencies in company procedural manuals.